police say the blue tooth technology makes it even harder to catch crooks. once they install the devices, they can nab the number off your card from as far as 100 yards and they never have to return to recover the skimmer. what is more, this universal gas pump key is making it even easier for thieves to install these new skimmers. >> it is virtually indetectible. >> reporter: he leads a team looking into dozens of blue tooth skimming cases in the past two months. investigators have recovered nine skimmers and recorded 300 victims of credit card fraud in the bay area. >> so a single key would open the credit card access door to any gas pump. >> reporter: that's right. one key opens the majority of gas station pumps. like this one in san jose. this one in mountain view. and this one in sunnyvale. it is simple. thieves copy the keys and install skimmers wherever they can. >> police tell us they have uncovered four skimmers at this gas station. >> no. >> reporter: you could change the locks to protect your customers' information. >> reporter: plais say they advi